Can I have the complete set of images that you are trying to stitch please?

Is the problem that the images do not stitch accurately or is it about the orinetation of the stitched panorama?

If orientation is the problem then you can fix that with the Vanishing point and Yaw,pitch, Roll tools in the Panorama Editor. Set the Vanishing point on the nadir and then use the Y/P/R tool to alter the pitch.

Here are some screenshots using a rolled image set 3shots using Sigma 8mm 3.5 on a Nikon DX witgh Mrotaror C head.

1. Because the lens has no electrical connection to the camera so lens data is not recorded in the EXIF you need to 'tell' APP/APG that these are fisheye images and that the focal length is 8mm in the Image properties dialogue, and check and set the crop circle to fullframe - screenshot 1.

2. Set the Default crop to Maximum projection range - screenshot 2.

3. Then all should go well - run Detect; then use the Vanishing point and Yaw,Pitch,Roll tools in the Panorama editor to re-oirientate the pano as described in my earlier post; then Render - screenshot 3 is my stitch with no further editing or manual intervention.

4. I think you should be able to use just 6 shots around rather than 12.